We have proposed to install photovoltaic (PV) panels parallel to the flat roof of a building with small gap between them. The gap may cause a pressure equalization effect on the PV panels, resulting in a reduction of the wind forces. In addition, the wind pressures acting on the waterproofing system will decrease too. In the present paper the wind pressures underneath the PV panels are evaluated by a numerical simulation using the unsteady Bernoulli equation together with the time history of external pressure coefficients on the roof of a building model obtained in a wind tunnel.
